I have a single MacBook Pro partitioned into two drives, each running a copy of Mountain Lion. In Partition X, I would like to disable Spotlight from indexing Partition Y. In Partition Y, I want to disable Spotlight indexing of Partition X.
Under System Preferences > Spotlight > Privacy, setting Partition X to prevent indexing of Partition Y also prevents Partition Y from indexing Partition Y. I.e., the privacy settings are preserved across partitions. I am looking for unique privacy settings for each partition.